


Becoming

by queenhomeslice



Series: Poly Promptis: Noctis/Prompto/Reader Pairings [5]
Category: Final Fantasy XV
Genre: Alternate Universe - Succubi & Incubi, Chubby Reader, Curvy Reader, F/M, Fluff and Hurt/Comfort, Getting Together, Incubi Becoming Human, Incubus Noctis Lucis Caelum, Incubus Prompto Argentum, Literal Sleeping Together, Multi, Polyamory, Promptis - Freeform, Spitroasting, Succubi & Incubi, Threesome - F/M/M, fat reader, plus size reader
Language: English
Status: Completed
Published: 2019-12-03
Updated: 2019-12-03
Packaged: 2021-02-25 23:27:22
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,857
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21653734
Author URL: https://archiveofourown.org/users/queenhomeslice/pseuds/queenhomeslice
Summary: Part 2 to Open WindowsWhen Prompto asks if he can bring a friend into your bedroom, things get...interesting.
Relationships: Noctis Lucis Caelum/Reader, Prompto Argentum/Noctis Lucis Caelum, Prompto Argentum/Noctis Lucis Caelum/Reader, Prompto Argentum/Reader
Series: Poly Promptis: Noctis/Prompto/Reader Pairings [5]
Series URL: https://archiveofourown.org/series/1536328
Comments: 16
Kudos: 88





	Becoming

**Author's Note:**

> I know I said I wouldn't do it but I literally couldn't help myself, fuck
> 
> \-----  
> Disclaimer: I do not own nor am affiliated with SqEn, Final Fantasy, or Final Fantasy XV

“Hey can I...introduce you to a friend?” Prompto leans his head sideways to look at you. You’re both in post-coital bliss, lying naked on your backs, coming down from the rush of adrenaline and endorphins. Prompto came four times and he’s done for the night, but he stills stays after if you ask him to—which is practically every night since you first left your window open. 

You meet his gaze and smile. “Uh, sure?” 

“Really?” Prompto’s bright blue eyes light up like he’s seen a chocobo—over the time you’ve come to know the bubbly incubus, he’s expressed his love for the pack birds more times than you can count. “You’ll let me bring a friend into your room?” 

“As long as they’re as nice as you,” you say, shivering a little in anticipation. 

“He totally is. His name’s Noctis. Can he come tomorrow?” 

You nod. “Sure thing, Prompto.” You yawn—the sex with Prompto is consistently mind-blowing, but you are human after all, and his stamina does a fine job of wearing you out. You groan as you haul yourself out of bed and to the bathroom, brushing your teeth and relieving yourself. Prompto watches as you come back in the bedroom and pull on your discarded pajamas and underwear. He’s naked as usual, as always—looking both delicious and oddly innocent as he reclines in your bed. You crawl back under the covers and Prompto moves to cuddle you immediately, softly humming a mystical lullaby as you drift off to sleep. 

The next night, you don’t even wait for the true evening to come—you throw open your window as soon as you get home from work. Prompto’s perched on the windowsill within minutes, smiling. 

“Eager today, aren’t we?” He laughs airily. 

“We don’t have to start now—I mean, unless you wanted to. I’m sorry, I just...wanted to see you.” 

Prompto stares at you and blushes, cute pink color rising from his toes to the tips of his ears. You witness a strange thing happen—his white horns seem to shrink in size, just a little—and they weren’t even that big to begin with. 

“Your horns,” you whisper as Prompto climbs into your bedroom and stands. “They...they shrunk?” 

“Oh man. Oh man, oh _shit_ ,” says Prompto, slightly panicked. “Dude, an incubus’ horns only shrink when...when a human falls in love with them.” He looks at you, wide-eyed. “You’re going to turn me if you’re not careful.” 

“I’m—I’m sorry!” you cry. “Does it—hurt? I don’t want to hurt you, Prompto. You can...find another human, if you want. I promise I’ll understand, I don’t want to...” 

“No,” says Prompto quietly, reaching out to cup the side of your face. “I would be honored to turn for you. I’ve never...had a human love me before. And I’ve never...I’ve never loved one back.” Prompto smiles and bends down to kiss you. 

There’s a cough from the window, and Prompto breaks the kiss to turn around. You peer behind him and see another incubus squatting in the open window. This one is of smiliar build and size to Prompto, but his hair is a silky jet-black to match his horns, tail, and wings. His blue eyes are a little grayer and darker than Prompto’s, and he’s got beautiful, exotic features. Where Prompto is pale, this one is tanner, with a little bulkier muscle definition, but still lean. He grins as Prompto steps to the side and turns, bowing dramatically. 

“At ease, Prom,” says the other incubus in a deeper, huskier voice than his light, golden counterpart. 

Prompto’s giggling as he stands and puts his arm around you. “___________, this is Noctis. He's the prince of the incubi.” 

Your eyes flit back and forth from Prompto to Noctis. “You think—you think the _prince_ of your kind is going to like...me?” 

Prompto nods. “Of course he will,” he purrs. “Why wouldn’t he?” He looks to his prince. “Isn’t she cute, Highness?” 

Noctis hums appreciatively and strides forward. He gives off an aura totally different from Prompto—you realize that it must be the royal blood thrumming through his veins. Noctis leans down close, inches from your face, and bares his fangs and his long, pink tongue. 

“Prom’s talked a lot about you, _____________. Let’s see if you deliver.” 

“Oh, _fuck_ , that’s so good...keep doing _that_...” Prompto’s voice trails off into high pitched whines as he bucks wildly into your mouth, fingers knotted in your hair as he uses you. It’s all you can do to keep your mouth open and your tongue moving around his thick, hard shaft. But every time you attempt to even move away from Prompto’s cock, Noctis makes you move even more forward, choking on the pretty blond in front of you. 

Noctis is buried balls-deep in your pussy from behind, growling heatedly, grabbing your fleshy, fatty hips in his long, sharp fingers and kneading hard enough to bruise. Somewhere in the delusional part of your brain, you hope he does bruise you. He’s already come twice and he’s still going, mounting you like it’s his gods-given right. The slick sounds of skin against skin, his heavy balls hitting your sensitive core, and the way that Noctis and Prompto are groaning your name is enough to have another dry orgasm shake your soft, naked body. You’ve never taken two men at once, never been so thoroughly fucked from both ends; the sensations are overhwelming. There are tears and snot streaming down your face as Prompto releases into you for the third time, sniffling and crying and moaning affectionate sweet-nothings as you gulp around him again. 

The sight of Prompto boneless and delirious with pleasure is what does Noctis in for his third time—he pumps his hips wildly and rough as more of his juices gush inside of you. You feel too full, too sensitive—and yet when Noctis finally pulls out, allowing his cum to drip from your used pussy and down your thick thighs, you feel weirdly empty. Prompto drags his flagging cock from your lips, and collapses on your bed, gathering you in his arms before you fall over from weak, shaky limbs. 

“Holy shit,” says Prompto, peering over your head and staring at his prince lovingly. “That was so good. Wouldn’t you agree, Noct?” 

“Mmmmmm, yeah,” says the prince in a lazy, authoritative voice. “She holds up pretty good. I approve.” 

“Thanks,” you croak, voice all wrecked and hoarse from having Prompto’s cock down your throat for who-knows-how-long. 

Noctis laughs and curls up around your back, pressing soft kisses to the back of your neck and the tops of your shoulders. “You found a good one, Prompto...” Noct’s voice drifts into silence as you pass out from sheer exhaustion. Whatever else the two incubi talk about while you’re asleep is lost as you enter into dreams. 

You wake up in the middle of the night—your window is shut, but Prompto’s still there. The lamp is on, and the first thing that strikes you about him is that his tail seems shorter and not as shiny, and his white horns are nearly invisible, nestled in his spikes of blond hair. His wings look smaller and less sturdy—you reach out to touch them delicately, and Prompto lets out a yelp, jumping himself awake instantly. 

“Ouch!” Prompto cries, painfully, falling gracelessly from your bed and onto the floor. “What the hell was that?” 

“Oh—Prompto!” You scramble up and over the side, dragging Prompto into your arms. He hisses a little as his wings brush your nightgown. “Your wings—are you hurt? What’s wrong? All I did was touch them, pretty lightly—I didn’t mean to scare you, or hurt you...” You feel emotional in spite of yourself. 

“My wings feel like they’re on fire,” Prompto gasps. He reaches up and pats his head, eyes widening in terror as he feels for his horns. “My horns! They’re almost gone!” He bares his teeth. “Fangs?!” he blurts. 

You look at his pearly white teeth—they're still a little pointed, but nowhere near what they were when he first showed up all those weeks ago. “Not very pointy anymore,” you say sadly. You reach out and delicately lift his white tail, which has gone almost limp instead of its usual proud swishing. “Your tail...” 

“It’s happening,” Prompto whines painfully. “While you were asleep, I talked to Noct about it...he said that he was anxious to come because he was getting the sense that I wouldn’t be an incubus much longer...guess I’m falling for you faster than I anticipated.” He bites his lip as he lifts his weepy gaze. “He’s my best friend, and I’m going to miss him, but...I’m also excited to be with you, if you want me, once...once I’m fully human.” 

“Prompto, honey, I’d want you even if you didn’t change at all. I love you for you. Your fascination with chocobos, the way you like to take pictures with my camera, the way you help me beat hard video game levels...even if you stayed an incubus forever, I’d love you. Of course you have a home here, with me.” 

“Could Noct still...come visit?” 

“Of course! But...you won’t get jealous...what if he wants me?” 

Prompto laughs. “He’s the prince of all the incubi, and my best friend. I’m not sure I could even get jealous if I wanted to. We’ve...been together, before. It doesn’t satisfy us like humans do, but...it feels good, y’know? Because it’s him. I love him. And I love you.” He frowns suddenly. “That’s not...will you accept me like this? I know humans have multiple lovers sometimes, but if you don’t want him, then I understand.” 

You shake your head. “If he means that much to you, of course I’ll let him in the window. And hey—if you turn fully human, it’ll be better for him to be with you, right? You can satisfy him, like I’ve satisfied you.” 

Prompto’s face lights up. “You’re _right_. Oh man, now I’m not even scared anymore!” 

You stand and help Prompto back up to the bed, falling back into a restful sleep. 

It was inevitable, of course—Prompto turned fully human the next week. Noctis came to visit every night after that first one; and two weeks after that, he perched naked on the window ledge for the last time. He’d named a new successor to his kind, because now that Prompto was human, well—the affection that Noctis felt for him allowed the raven-haired prince to turn into a human as well. The three of you moved into a larger apartment, thanks to Noctis and Prompto quickly discovering that they could make a living by playing video games and streaming their progress. You sighed happily to yourself one evening as you made dinner, deleting all the old dating apps form your phone. All of the adults in your life had been so, _so_ wrong. Leaving your window open at night was the best thing you’d ever done. 


End file.
